Restructuring and Other Charges - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring payments related to staff reductions		$ 0.8	$ 0.3
Restructuring payments	$ 0.5	3.0	2.4
Restructuring charges		2.2	2.4
Restructuring payments related to employee costs		1.9	1.2
Employee Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring payments related to staff reductions	0.5
Restructuring payments	0.5	2.7	1.5
Restructuring charges		2.2	2.1
Facility Closing [Member] | Tenancy-related Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring payments	$ 0.7		0.9
Restructuring charges		$ 0.3	$ 0.3